Effects of Compressive Stress on Fluorescent Penetrant Indications of Fatigue Cracks in Titanium

Abstract

Although it has been generally accepted that compressive stress adversely affects the fluorescent penetrant indications of fatigue cracks, published supporting data was lacking. To begin to fill this data void, five titanium specimens containing low cycle fatigue cracks were repetitively processed with a standardized liquid penetrant procedure after known stresses had been applied. A fixture was designed to apply known amounts of compressive stress on the cracked surfaces over the range of 0 to 63.5 ksi. The penetrant indications were measured and analyzed with two independent techniques. Eddy current inspection data were also generated for comparison with the penetrant data. The liquid penetrant indications began to diminish immediately with the application of compressive stress. On the other hand, the amplitudes of the eddy current indications remained the same over the entire range of applied stress.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 2001
Accession Number
ADA404873

Entities

People

  • John C. Brausch
  • Noel A. Tracy

Organizations

  • Universal Technology Corporation (United States)

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms
  • Space

DTIC Thesaurus Topics

  • Air Force
  • Air Force Research Laboratories
  • Amplitude
  • Detection
  • Digital Images
  • Dwell Time
  • Eddy Currents
  • Image Processing
  • Inspection
  • Intensity
  • Manufacturing
  • Materials
  • Measurement
  • Shot Peening
  • Strain Gages
  • Turbines
  • X Rays

Readers

  • Structural Health Monitoring of Composite Structures.
  • Systems Analysis and Design